Compiler

New Features

• KT-7745 Support named arguments in their own position even if the result appears as mixed
• KT-34847 Lift restrictions from kotlin.Result

Performance Improvements

• KT-14513 Suboptimal compilation of lazy delegated properties with inline getValue

Fixes

• KT-19234 Improve "Supertypes of the following classes cannot be resolved" diagnostic
• KT-21178 Prohibit access of protected members inside public inline members
• KT-24461 Expect interface with suspend function with default arguments causes runtime error
• KT-25514 Support usage of function reference with vararg where function of array is expected in new inference
• KT-26435 Bad frame merge after inline
• KT-27825 Gradually prohibit non-abstract classes containing abstract members invisible from that classes (internal/package-private)
• KT-27999 Generic type is fixed too early for lambda arguments
• KT-28940 Concurrency issue for lazy values with the post-computation phase
• KT-29242 Conditional with generic type Nothing inside inline function throws java.lang.VerifyError: Bad return type
• KT-30244 Unable to infer common return type for two postponed arguments
• KT-30245 Wrong type is inferred for lambda if it has expected type with an extension receiver
• KT-30277 Relax the "no reflection found in class path" warning for KType and related API
• KT-30744 Invoking Interface Static Method from Extension method generates incorrect jvm bytecode
• KT-30953 Missing unresolved if callable reference is used in the place in which common super type is computing
• KT-31227 Prohibit using array based on non-reified type parameters as reified type arguments on JVM
• KT-31653 Incorrect transformation of the try-catch cover when inlining
• KT-31975 No diagnostic on error type
• KT-32106 New type inference algorithm: IDE shows error but the code compiles succesfully
• KT-32138 New type inference: invoking type-aliased extension function red in IDE, but compiles
• KT-32168 Problem in IDE with new type inference and delegate provider
• KT-32243 New type inference fails
• KT-32345 New type inference error when using helper method to create delegate provider
• KT-32415 Type mismatch on argument of super constructor of inner class call
• KT-32423 NI: IllegalStateException: Error type encountered: org.jetbrains.kotlin.types.ErrorUtils$UninferredParameterTypeConstructor@211a538e (ErrorType)
• KT-32456 NI: "IllegalStateException: Error type encountered" when adding emptyList to mutableList
• KT-32499 Kotlin/JS - new type inference with toTypedArray() failure
• KT-32742 Gradle/JS "Unresolved Reference" when accessing setting field of Dynamic object w/ React
• KT-32818 Type inference failed with elvis operator
• KT-32862 NI: Compilation error "IllegalArgumentException: ClassicTypeSystemContextForCS couldn't handle" with overloaded generic extension function reference passed as parameter
• KT-33033 NI: Nothing incorrectly inferred as return type when null passed to generic function with expression if statement body
• KT-33197 Expression with branch resolving to List<…> ultimately resolves to MutableList<…>
• KT-33263 "IllegalStateException: Type variable TypeVariable(T) should not be fixed!" with generic extension function and in variance
• KT-33592 NI: Missed error in IDE — Unsupported [Collection literals outside of annotations]
• KT-33932 Compiler fails when it encounters inaccessible classes in javac integration mode
• KT-34029 StackOverflowError for access to nested object inheriting from containing generic class at org.jetbrains.kotlin.descriptors.impl.LazySubstitutingClassDescriptor.getTypeConstructor
• KT-34282 Missing diagnostic of unresolved for callable references with overload resolution ambiguity
• KT-34391 IDE, NI: False negative EXPERIMENTAL_API_USAGE_ERROR with callable reference
• KT-34500 CompilationException when loop range is DoubleArray and loop parameter is casted to super-type (e.g. Any, Number, etc.)
• KT-34647 Gradually rename experimentality annotations
• KT-34649 Deprecate -Xexperimental flag
• KT-34743 Support trailing comma in the compiler
• KT-34786 Flaky type inference for lambda expressions
• KT-34820 NI: Red code when expanding type-aliased extension function in LHS position of elvis
• KT-35101 "AssertionError: Mapping ranges should be presented in inline lambda" with a callable reference argument to inline lambda
• KT-35168 NI: "UninitializedPropertyAccessException: lateinit property subResolvedAtoms has not been initialized"
• KT-35172 NI: False positive type mismatch if nullable type after elvis and safe call inside lambda is returning (expected type is specified explicitly)
• KT-35224 NI: Java call candidate with varargs as Array isn't present if SAM type was used in this call
• KT-35426 IncompatibleClassChangeError: Method 'int java.lang.Object.hashCode()' must be Methodref constant when invoking on super with explicit generic type

Docs & Examples

• KT-31118 Provide missing documentation for StringBuilder members

IDE

New Features

• KT-27496 Color Scheme: allow changing style for suspend function calls
• KT-30806 Add IntelliJ Color Scheme rules for property declarations
• KT-34303 IDE should suggest to import an extension iterator function when using for loop with a range
• KT-34567 Feature: Auto add val keyword on typing data/inline class ctor parameters
• KT-34667 Add auto-import quickfix for overloaded generic function

Performance Improvements

• KT-30726 Editor is laggy if the code below a current line has unresolved reference
• KT-30863 IDE freeze on editing with "Add unambiguous imports on the fly" turned on
• KT-32868 Provide incremental analysis of file when it is applicable
• KT-33250 KtLightClassForSourceDeclaration.isFinal() can be very slow (with implications for class inheritor search)
• KT-33905 Optimize imports under reasonable progress
• KT-34956 UI Freeze: PlainTextPasteImportResolver
• KT-35121 Add support for KtSecondaryConstructors into incremental analysis
• KT-35189 Support incremental analysis of comment and kdoc
• KT-35590 UI freeze in kotlin.idea.core.script.ScriptConfigurationMemoryCache when editing file

Fixes

• KT-10478 Move-statement doesn't work for methods with single-expression body and lambda as returning type
• KT-13344 Reduce visual distraction of val keyword
• KT-14758 Move statement up shouldn't move top level declarations above package and import directives
• KT-23305 We should be able to see platform-specific errors in common module
• KT-27806 UAST: @Deprecated(level=DeprecationLevel.HIDDEN) makes method disappear
• KT-28708 Java IDE fails to understand @JvmDefault on properties from binaries
• KT-30489 Kotlin functions are represented in UAST as UAnnotationMethods
• KT-31037 Lambda expression default parameter 'it' sometimes is not highlighted in a call chain
• KT-31365 IDE does not resolve references to stdlib symbols in certain packages (kotlin.jvm) when using OSGi bundle
• KT-32031 UAST: Method body missing for suspend functions
• KT-32540 UltraLight support for compiler plugins
• KT-33888 Bad indentation when copy-paste to trimIndent()
• KT-34081 Kotlin constants used in Java annotation attributes trigger "Attribute value must be constant" error
• KT-34316 UAST: reified methods no longer visible in UAST
• KT-34337 Descriptors Leak in UltraLightClasses
• KT-34379 "Implement members" with unspecified type argument: "AssertionError: 2 declarations in override fun"
• KT-34785 Enter handler: do not add 'trimIndent()' in const
• KT-34914 Analysis sometimes isn't rerun until an out of code block change
• KT-35222 SQL language is not injected to String array attribute of Java annotation
• KT-35266 Kotlin-specific setting "Optimize imports on the fly" is useless
• KT-35454 Weird implementation of KtUltraLightFieldImpl.isEquivalentTo

IDE. Code Style, Formatting

New Features

• KT-35088 Insert empty line between a declaration and declaration with comment
• KT-35106 Insert an empty line between a declaration and declaration with annotation

Fixes

• KT-4194 Code formatter should not move the end of line comment after if condition to the next line
• KT-12490 Formatter inserts empty line between single-line declarations in the presence of a comment
• KT-22273 Labeled statements are formatted incorrectly
• KT-22362 Formatter breaks up infix function used in elvis operator
• KT-23811 Formatter: Constructor parameters are joined with the previous line if prefixed with an annotation
• KT-23929 Formatter: chained method calls: "Chop down if long" setting is ignored
• KT-23957 Formatter tears comments away from file annotations
• KT-30393 Remove unnecessary whitespaces between property accessor and its parameter list in formatter
• KT-31881 Redundant indent for single-line comments inside lambda
• KT-32277 Space before by delegate keyword on a property is not formatted
• KT-32324 Formatter doesn't insert space after safe cast operator as?
• KT-33553 Formater does not wrap function chained expression body despite "chained function calls" settings
• KT-34049 Formatter breaks string inside template expression with elvis operator
• KT-35093 Formatter inserts empty line between single-line declarations in the presence of an annotation
• KT-35199 Wrong formatting for lambdas in chain calls

IDE. Completion

Fixes

• KT-15286 Support import auto-completion for extension functions declared in objects
• KT-25732 "null" keyword should have priority in completion sort
• KT-29926 Suggest lambda parameter names in IDE to improve DSL adoption
• KT-31762 Completion: Parameter name is suggested instead of enum entry in entry constructor
• KT-32615 PIEAE for smart completion of anonymous function with importing name inside of function
• KT-33979 No completion for functions from nested objects
• KT-34150 No completion for object methods that override something
• KT-34386 Typo in Kotlin arg postfix completion
• KT-34414 Completion works differently for suspend and regular lambda functions
• KT-34644 Code completion list sorting: do not put method before "return" keyword
• KT-35042 Selecting completion variant works differently for suspend and regular lambda parameter

IDE. Debugger

• KT-12242 Debugger: breakpoint in a class is not hit if the class was first accessed in Evaluate Expression
• KT-20342 Step Over jumps to the wrong position (KotlinUFile)
• KT-30909 "Kotlin variables" button looks inconsistent with panel style
• KT-32704 ISE "Descriptor can be left only if it is last "on calling function with expression body inside Evaluate Expression window
• KT-32736 Evaluate Expression on statement makes error or shows nothing
• KT-32741 "Anonymous functions with names are prohibited "on evaluating functions in Expression mode
• KT-33303 "Smart step into" doesn't work for library declarations
• KT-33304 Can't put a breakpoint to the first line in a file
• KT-33728 Smart Step Into doesn't work for @InlineOnly functions
• KT-35316 IndexNotReadyException on function breakpoint

IDE. Folding

• KT-6316 Folding of multiline functions which don't have curly braces (expression-body functions)

IDE. Gradle. Script

• KT-31976 Adding a space in build.gradle.kts leads to 'Gradle projects need to be imported' notification
• KT-34441 *.gradle.kts: load all scripts configuration at project import
• KT-34442 *.gradle.kts: avoid just-in-case script configuration request to Gradle
• KT-34530 Equal duplicate script definitions are listed three times in Preferences
• KT-34740 Implement completion for implicit receivers in scripts with new scripting API
• KT-35096 Duplicated “Kotlin Script” definition for Gradle/Kotlin projects
• KT-35149 build.graldle.kts settings importing: configuration for buildSrc/prepare-deps/build.gradle.kts not loaded
• KT-35205 *.gradle.kts: avoid just-in-case script configuration request to Gradle while loading from FS

IDE. Hints. Parameter Info

• KT-34992 UI Freeze: Show parameter info leads to freezes

IDE. Inspections and Intentions

New Features

• KT-8478 Make 'Add parameter to function' quick fix work to parameters other than last
• KT-12073 Report IDE inspection warning on pointless unary operators on numbers
• KT-18536 Provide proper quick fix for accidental override error
• KT-34218 Merge 'else if' intention

Fixes

• KT-17659 Cannot access internal Kotlin declaration from Java test code within the same module
• KT-25271 "Remove redundant '.let' call" may introduce expression side effects several times
• KT-29737 "Make internal/private/protected" intention works for either expect or actual side
• KT-31967 Typo in inspection name: "'+=' create new list under the hood"
• KT-32582 Ambiguous message for [AMBIGUOUS_ACTUALS] error (master)
• KT-33109 "Add constructor parameters" quick fix should add default parameters from super class
• KT-33123 False positive "Redundant qualifier name" with inner class as constructor parameter for outer
• KT-33297 Improve parameter name in Add parameter to constructor quick fix
• KT-33526 False positive "Redundant qualifier name" with enum constant initialized with companion object field
• KT-33580 False positive "Redundant visibility modifier" overriding property with protected set visibility
• KT-33796 INVISIBLE_SETTER: quick fix "Make '' public" does not remove redundant setter
• KT-33902 False positive for "Remove explicit type specification" with type alias as return type
• KT-33933 "Create expect" quick fix generates the declaration in a default source set even if an alternative is chosen
• KT-34078 ReplaceWith does not work if replacement is fun in companion object
• KT-34203 "Add constructor parameter" fix does not add generics
• KT-34297 "Add 'replaceWith' argument" inserts positional instead of named argument
• KT-34325 "Control flow with empty body" inspection should not report ifs with comments
• KT-34411 Create expect/actual quick fix: focus is lost in the editor (193 IDEA)
• KT-34432 Replace with safe call intention inserts redundant elvis operator
• KT-34603 "Remove redundant '.let' call" false negative for reference expression
• KT-34694 "Terminate preceding call with semicolon" breaks lambda formatting
• KT-34784 "Indent raw string" intention: do not suggest in const
• KT-34894 Action "Add not-null asserted (!!) call" doesn't fix error for properties with omitted this
• KT-35022 Quickfix "change to var" doesn't remove const modifier
• KT-35208 NPE from PerModulePackageCacheService
• KT-35288 False positive "Remove braces from 'when' entry" in 'when' expression which returns lambda

IDE. Navigation

• KT-30736 References for import alias from kotlin library not found using ReferencesSearch.search

IDE. Refactorings

• KT-18191 Refactor / Copy multiple files/classes: package statements are not updated
• KT-18539 Default implement fun/property text shouldn't contain scary comment
• KT-28607 Extract/Introduce variable fails if caret is just after expression
• KT-32601 Introduce variable in unformatted lambda causes PIEAE
• KT-34459 Change method signature with unresolved lambda type leads to error
• KT-34971 Refactor / Copy for declarations from different sources throws IAE: "unexpected element" at CopyFilesOrDirectoriesHandler.getCommonParentDirectory()

IDE. Run Configurations

• KT-34632 Kotlin/JS: Can not run single test method

IDE. Script

• KT-34688 Many "scanning dependencies for script definitions progresses at the same time

IDE. Tests Support

• KT-33787 IDE tests: Not able to run a single test using JUnit

JS. Tools

• KT-35198 Kotlin/JS: with references to NPM/.kjsm library DCE produces invalid resulting JavaScript

JavaScript

• KT-30517 KJS generates the wrong call for secondary constructor w/ default argument when class inherited by the object expression
• KT-33149 JS: lambda is not a subtype of Function<*>
• KT-33327 JS IR backend works incorrectly when function and property have the same name
• KT-33334 JS IR backend can't access private var from internal inline function

Libraries

• KT-17544 JS: document array destructuring behavior
• KT-33069 StringBuilder common functions
• KT-33447 runCatching docs suggests it catches exceptions but it catches throwables
• KT-35175 Clarify documentation for XorWowRandom
• KT-35299 Float.rangeTo(Float): ClosedFloatingPointRange doesn't exist in the common stdlib.

Reflection

• KT-14720 Move KClass.cast / KClass.isInstance into kotlin-stdlib
• KT-33646 Make KClass.simpleName available on JVM without kotlin-reflect.jar
• KT-34586 Make KClass.qualifiedName available on JVM without kotlin-reflect.jar

Tools. CLI

• KT-29933 Support relative paths in -Xfriend-paths
• KT-34119 Add JVM target bytecode version 13
• KT-34240 CLI kotlinc help -include-runtime has redundant space

Tools. Gradle. JS

New Features

• KT-30659 Run NodeJS debugger when running debug gradle task from IDEA
• KT-32129 Gradle, JS, Karma: debug
• KT-32179 Gradle, JS, DSL: allow npm in root dependencies section of single platform projects
• KT-32283 Configure webpack mode
• KT-32323 Gradle, JS, webpack: support optimized webpack bundle
• KT-32785 Gradle/JS + Webpack: Asset bundling in distributions folder

Fixes

• KT-30917 Gradle, Tests: Inner classes mapped incorrectly in short test fail message
• KT-34946 [Kotlin/JS] DCE require some/all transitive dependencies. Invalid compilation result otherwise
• KT-35318 KJS: IllegalStateException on clean build with left-pad package and generateKotlinExternals=true
• KT-35428 [Gradle, JS] Gradle dependency with invalid package.json
• KT-35598 [Gradle, JS] Actualize NPM dependencies in 1.3.70

Tools. Gradle. Multiplatform

• KT-35126 Support Gradle instant execution for Kotlin/JVM and Android tasks

Tools. J2K

• KT-16774 UI Freeze: J2K, PlainTextPasteImportResolve: IDEA freezes for 10+ seconds when copy-pasting Java code from an external source to Kotlin file
• KT-19574 Code with inferred default parameters and parameter vs property name clashes
• KT-21811 Convert string concatenation into a multiline string
• KT-32551 New J2K: Non-canonical modifiers order inspection is not applied during conversion of a super inner class
• KT-34673 J2K: first comment in function (if, for, while) block is moved to declaration line of the block
• KT-35152 J2K breaks formatting by moving subsequent single-line comments to the first column

Tools. Scripts

• KT-34274 Add support for [@CompilerOptions](https://github.com/CompilerOptions) annotation in kotlin-main-kts
• KT-34893 Update apache ivy version in kotlin-main-kts
• KT-35413 Implement "evaluate expression" command line parameter and functionality in the JVM cli compiler
• KT-35415 Implement script and expression evaluation in the kotlin runner
• KT-35416 load main-kts script definition by default in the jvm compiler, if the jar is available

Tools. kapt

• KT-30164 Default field value not transmitted to Java source model for mutable properties
• KT-30368 Deprecated information not transmitted to Java source model
• KT-32832 Kapt: Turn worker API on by default
• KT-33617 KAPT, Java 9+: "IllegalStateException: Should not be called!"
• KT-34167 Kapt: Annotation Processor incorrectly marked as isolating causes full rebuild silently.
• KT-34258 kapt.incremental.apt=true makes build failed after moving annotation processor files